Meireles scored his first senior goal on 25 May 2003, in a 2–1 home win against C.F. União where he fired from 30 metres into the net.[3] He finished his second season with 26 appearances, to help his team finish in sixth position.

On 19 February 2006, Meireles scored his first goal for the Dragons in his 50th league appearance, giving a 1–0 home victory over C.S. Marítimo.[15] He netted his second three matchdays later in a 2–0 triumph against Vitória de Setúbal,[16] as the season ended with double conquest.

In the following four years, during which the domestic league was won three additional times, Meireles featured regularly in Porto's midfield, often partnering Fernando and Lucho González. He scored his first goal in the Champions League during the 2006–07 edition, in a 1–1 last-16 home draw against Chelsea, coached by his former manager José Mourinho.[17]

Meireles was handed his first league start on 19 September 2010, in a 2–3 away loss against Manchester United.[22] On 16 January 2011, he scored his first goal for his new team in a 2–2 home draw against Everton, which coincided with Kenny Dalglish's first home game back as manager.[23] His second came six days later in a 3–0 win at Wolverhampton Wanderers, when he struck a dipping 25-yard volley into the top corner of the net in the 50th minute.[24]

In the second match of the 2011–12 campaign, away against Arsenal, Meireles played 19 minutes after replacing Dirk Kuyt, and provided the assist for Luis Suárez in a 2–0 win which marked the first time they had defeated the opposition on their ground in 11 years.[28] On 31 August, however, he asked to be transfer listed.[29]

With Chelsea in the market for a midfielder following a long-term injury to Michael Essien, and an unsuccessful bid to acquire Luka Modrić from Tottenham Hotspur,[30][31] the former signed Meireles to a four-year deal on 31 August 2011, for an undisclosed fee reported to be in the region of £12 million.[32][33] He chose the squad number 16, due to the fact he often wore it when on international duty,[34] and later claimed he never wanted to leave Liverpool but that the chance to work with André Villas-Boas, with whom he had spent a short period of time at Porto, was too good an opportunity to turn down.[35][36]

In December 2012, Meireles was handed an eleven-match ban by the Turkish Football Federation for spitting at a referee.[48] The alleged actions were followed by accusations of homophobic remarks after he received a second yellow card in the second half of a 1–2 away defeat to rivals Galatasaray SK.[49] However, the ban was reduced on appeal to four games after it was ruled that he could not have spat at the referee, being only guilty of verbal abuse.[50]

Meireles' first game for the Portuguese senior team took place on 15 November 2006, when he played the entire 3–0 win over Kazakhstan for the UEFA Euro 2008qualifiers.[73][74] He was picked for the final stages in Austria and Switzerland,[75] marking his debut in a major international competition with a goal in the 2–0 group stage success against Turkey (also his first), after entering the pitch in the 83rd minute.[76] He then started alongside several reserve players in the final group clash, a 0–2 defeat to Switzerland;[77] four days later, he replaced João Moutinho during the first half of an eventual 2–3 quarter-final loss against Germany.[78]

Meireles could play in any position in the midfield, but preferred to operate as a central midfielder.[85] He was capable of being deployed in both a defensive and attacking role, depending on the players available and coaches' strategies. At Porto, he was used initially as a defensive midfielder, but tactical factors saw him swift to attacking midfielder;[86][87] in an opposite approach, when Paulo Bento was appointed as the Portuguese head coach in 2010, the player was eventually played in a more defensive position after starting out in attacking midfield.[88]

Meireles was a fan of tattoos since he was 18 years old. Numerous images adorned his body, including those of Ivone and Lara. He also had a large design of a black and red Chinese-style dragon, drawn in two stages and sprawling across his back,[95][96] and a huge necklace tattoo with a skull, drawn one week after his twenty-eighth birthday.[97]

After moving to Anfield, during an interview with Liverpool's official website, Meireles jokingly said that he wanted to win the "ink championship" against teammates Daniel Agger and Martin Škrtel, due to their shared affection for tattoos.[98][99]